Yoke and gimbal



Jan. 15, 1963 R. F. KUHN, JR 3,073,630

YOKE AND GIMBAL Filed May 29, 1959 s Sheets-Sheet 1 INVENTOR. RALPH F.KUHN JR.

BY? 5 I ATTORNEY R F. YOKE AND GIMBAL Jan. 1

3 Sheets-Sheet 2 Filed May 29. 1959 INVENTOR- RALPH F. KUHN FIG- 4ATTORNEY Jan. 15, 1963 R. F. KUHN, JR 3,073,630

YOKE AND GIMBAL Filed May 29, 1959 3 Sheets-Sheet 3 FIG. 6

INVENTOR. RALPH F. KUHN JR.

BYWM44,%

ATTdRNEY Patented Jan. 15, 1953 "UnitedStates Patcnt.'Oice sriiiiw 3 073630 F1656 is a partially cutaway view along line 5-5 v, showing thedetails of construction of the support mem- Ralph F; gfggf' agg g figiassignor to hers and the manner in which they engage the close yokeNorth American Aviationylnc. g g v FiiedMay 29, 1959, Ser.No;'816,974 5Rererrrng now to FIG. 1 WhlCh shows the general fiiCiaims. (Cl. 287-1-1)orientation of the present invention, it can be seen that i a rocketengine 7 is mounted to a missile 8 by means of This invention relatesgenerally to gimbals and more a gimbal indicated generally by the arrow9. The gimrparticularly to alight weight universal rocket engine bal 9is preferably made up of a pair of missile body gimbal which willtransfer large thrust from a rocket 10 support'mernbers iti mounted tothe missile ti and a pair engine toa missile body. i of rocket enginesupport members 11 mounted to the Thereis a continuing need forlargerand larger rocket engine 7; said support members being movablymounted engines in order to put larger and larger payloads into togetherby means of a yoke member 12. A rotary actuathe "sky and the spaceabove. One major problem in tor 13 is provided to rotate the rocketengine 7 relative conjunction with the .use 'of larger rocket engines isthat 15 to the missile body 8 about one: axis in a manner which somemeans such as a universal gimbalfmust be;provided i will be described inmore detail below; A- second rotary in order to be able to varytthedirection of the thrust actuator (not shown) is located on the far sideof the .of the rocket engine. Further, many timesTitis desired jgirnbal9-to rotate the engine 7, relative to the missile touse what iscallediaringgimbal which has a hole b odyj8abouta second axis. i.through the center of it; This hole is particularly ad- -As mentionedabove the primary reason that the yoke vantageous-in'thata shortstraight flexible propellant line members ofprevious ring gimbals had tobe made so may be installed extending throughthe hole whichwill 1 heavyis that they were so designed that bending stresses 'carry morepropellant to therocket engine easier. Until were introduced into theyoke when the rocket engine H this time, the engineers have had toinakethe ring gimbal thrustnwas applied. FIG, 2 discloses a simplifiedyoke larger as the size of the rocket engine is increased. The andsupport members in orderto illustrate the principle main problemencountered in thedesign of ring gimbals upon which that presentinvention works and how the isithat the yoke which transfers the rocketthrust force yoke memberi which carries the thrust forces from the. fromthe engine to the missile body must be made very rocketengine tothe"missile;body is loaded only in tension.

heavy in order towork satisfactorily. More specifically, A fiitheipfesefii'invention is colltiftllous Y when thethrustloadis appliedit tends tobendthe-yoke or baryrnernber 114 which isof nearly constantcrosst which binds theradial bearingswhich aremounted be iS Q T y ke m 41pl'cwided with a first tween the yolge and thesupportqmembers on theengine semi-circular arcuate portion 15 and a second semi- ,and: then-iissile bqdy; In order to prevent the bending circular ar cuateportion 16 which are spaced along a load from bending the yoke andthereby bind the bearings fi Y i 21130 h a third Semi-circular ithasbeeninecessaryz tomake the r'yokemuchheavier=witl1 farc a ep r ionlfiand a fourth semir fl i P ianmore cornplicated structure.tThereforeysuch priorldetinn ilgwhiclr are spaced alon a second yokeaxis gili ,sign's have-not only added unwanted dead' weightgto thewhichlerrtends atra right aiig ley to jthe first yoke nests-.5 mmissilehutalsoshave iuereasedsthe cost Gr ndmaster, I ""Asfcan be seenhthe endsof the jfirst arcuate portion Withthese disadvantagesand.problemsinr-lmindit is i re in es y j ned f the ends at h r anobjectfof; thi s invention toprovideiia new,-better' yoke 40 and fwrih pl fl en t W QQ WHG l for gimbahw 1 1 f i g endofithesecondportien 1661Cintegrally joined with the y i it is a further-;objectloimthis n ventionto a provide a fll f hflends Of'tll thir en Q hfPQfi Q ,8 and iglightweighti okemember fona gimbal which-has; a simp1e 19 respectivelylfiachjof the arcuate portions 15, 16,":18 ,eonstru'ctionland will tkelarger-loads more easilythan a is q s with 5 1111161 r rc bearing.prionyoke members. surf ace designated as15trfi16ay18a, and 19rzrespectively. v j stillturther objectnof'thi invention isi 5 hOl-fld.hilti it is preferred thaffl fi Mi i afrocket enginef ring gimb r vvhi li 5 member 14 be made] from asinglepieee of rnetal in orderto'bbtain amore'efiicients'tructure, the yoke ni'erni Qtheyok of theringgirnb'aL-will only amnesia i wherebysnobendingrnqmentsqwill b d dj 1jber ld-could also be fabricated from several pieces of j m 1a light Weh o v l ich are joined together by ;somesuitable means i ou itense i l 0th gimbal. th y9 a mmerse b r. h Wna An additionaltobject.of this? njilibi provide; Ini order-to transfer ;the thrust bfkj-the ro clret enginrmcket engine i n -td 1t 1s 71-50 desianedfithatfitjn de'signaied bribes i Fe to e k a P is iloaded 1 m or e ett icieritlydaythe rocket engiriethrust e e embe 's 2 2 which W -"b ".th'anxprior rocket, engine gimbalswhereby afili ht moun'ted to arocket engine (not shown) wouldpreferably; 7 balmay'accomplishthedesiredresult t i ed;Theensinesilppeitmembers 2 1, an Zahara otheriaiidrf rrher, objects-0 jr u b r n f c sli "a d fi tr pec'tiv y. which m n. fl i x i are forcedagainst theiower bearing surtacesxfia and Ma heehgm ii l of the bearingsurfaces-15a and 16m rtions lll, 42; 43, 'andf44are:locatedinoppqs thebearing surfaces 35 36a,38aand 39a respectively. Liquid rocket enginesnormally onlyweightlapproirimately 2 to 5% of the thrusttthat they willgenerate; therefore, each of the lightweight arcuate portions is,preferably (18- signed. with across section, and-therefore strngth,:which is. approximately 5 to %1ofthe bar member '34 when 4 arotafryfitype pqsitioningfactuatoris used to control thedirectidnofengine thrust. ,If linear piston typepactuators j are usedjtowp osition ther'ocketxjengihe and thereby con- 1 the diiectiodofthrust; 'the'lightweighti arcuate por relative to the yoke member 14. Itshould be particularly noted that the inner bearing surfaces liSa and16a are spaced apart along the yoke axis 17 a distance equal to thediameter of the inner bearing surfaces 113a and 19a. The

bearing surfaces 180: and 1% are likewise spaced apart along the yokeaxis 2% a distance equal to the diameter With this construction thevarious semicircular shearing surfaces are tangent to each other at theends of the various arcuate portions 1516, 13 and 19 which lie in aplane passing through the yoke axes 17 and 20. 'The points of tangencybetween bearing surfaces 150: andlfia, 15a and 19a, and 16a and 19a aredesignated as Fail, 31 and 32 respectively. The point of tangencybetween bearing surfaces 16a and 18a can not be seen in FIGJZ. With thisstructure, when the yoke member '14 isloadediby the force of the rocketengine F an d the reaction forcesoi the missile E. the

teaches the principle upon which the present invention operates well, apreferred embodiment of this invention includes additional structure andhas a configuration as V M t t which mayeasily receive and engage theouter race ofa conventional radial roller bearing on an engine and bodysupport member. .Each of these circular apertures is tangent to two ofthe other three apertures. Thepoint of tangency 47 between the bearingsurfaces 35a and 39a is particularly well shown in FIG. 3.

An arcuate projection 46 is located on arcuate portion 36 with a seriesof threaded bores it; formed therein to receive the mounting bolts bywhich a positioning acin the top-view of the yoke member 34 shown inFIG.

l, it isseen that the various arcuateportions of the yoke member arejoined to form a generally sguareshapewith a hole passingdown throughthe middle of the yoke in order to allowa propellant conduit to passthrough the center of the gimbaL' For purposes of clarity, only the.engine support members and not the body support mern- V hers, areshownin FiGJ lL Referring now to FIG. 5

preferred embodiment of the yoke member 34 with means shown in FIG. 3.Here a continuousyokegor bar member 34- is shown which is basically thesame as yoke member 14 in FIG. 2. More specifically,.yoke member 54 isprovided witha first and second semi-circular arcuate portion 35 and 36-spaced along a first yoke agris ii'i and a third and fourthsemicircularfareuate portion 38 andm39 respectively spaced along asecondyoke akisAtl which extends at a right angle tqthefirstyGkeaXis-STEacliof these arcuate portions 35, 36, seats 39 has an innersemicircular bearing surface, designated as 3541,3651, 38a, and

gbelow the missile, a1series of lightweight arcuate por rnately 25% "asstrongjas the barrmember 34, sincewhen positioningjthe engine .theactuators sometimes tend to.

piushfitlie frocketiengine away from the missile ,body: with a:forc ewhiclifis-around 20% lof the thrust of theengin el Preterab lythelightweight arcuate portions are provided.

adapted to be mounted to a missile body-and a rocket engine mounted'toit. 1 Asshown, a first and a second engine support member 52 and 53 aremounted "to the yoke member 34- to transfer loads from the thrust of theI Enginesupport member 52 1 has a vertically extending upright portion54 with a bore $5 therethrough; saidborehavinga plurality of splines 56formed around the periphery thereof. 'Apluralityof I holes 57 areprovided in the support member 52in 'order to receive bolts by which thesupport member is mounted to the rocket engine. 1 In order to reducefriction; when the support members movrelative tothejy'oke member 34aseries of bearings are used various support members. a Y r "The detailsof the constructio'n of supp rtInemberSZ 1 and the bearings usedfinconjunction with it aredisplosed in, FIG. 6 wherein it can be seen thatthe uprightportion 354 has: a recess 58therein,"th'erebytorminganinwardly extendinglcylindrical portionjl59, 'A radial roller bearing 60is mounted with its inner race engaging" the peripheral rocket engine(not shown).

surfaceof cylindrical portion S9 and theupper half of its transfer therocket" thrust loads from. the support ber 52 to the yoke member 34 witha minimum of friction when the: yoke member 34s relativetothe supportmember 52. The lower half of the'outerLrace of thebearing 60Tengages theupper] surface of the' lightweight f'arcuate' .1 portion" 42 in ordertoftransfer the dead weight of rthe engine to the yoke 34 when themissile is ongthe launch pad. rollerithrust bearing lfil is tmounted'to-th' radial ibearingfill by means'ofits right handiraceiwhih "sbrazed I to the outer raceof the radial roller bearingfi fi mad mrighthand races of the thrustbearing '61 engage I the'upright portion 54and the side of the arcuatexportionsand prospectively in order-totransfer any lateral .loads during operation. I 'In order to furnishadditional T supp ort tor the cylindrical portion 595 a spacer block .63is I locatedin the reeesss fias shown held there by means l which is apictorial view of the t b wae h lrq a d/ h I b V to one of the ends ofsaid third and fourth portions respectively, theends of said secondportion beingintegrally and directlytjoined to'the other ofthe ends of,

said third and fourth portions respectively, each ofsaid semi-circularportions having an inner semi-circular hearing surface facing andextending concentric to the respective yoke axis, each of said innerbearing surfaces being tangent to two of the otherthree bearing surfacesat a point lying in a plane extending through the two yoke axes.

6. A yoke for a universal gimbal coniprising an endless bar member ofsubstantially constant cross section formed along a first yoke axis, anda thirdrand a fourthsernicircular portion spaced along a second yokeaxis which extends at a right angle to said first yoke axis, the ends ofsaid first portion being integrally and directly joined to one of theends of said and fourth portions respectively, the ends of said secondportion being integrally and directly joined to the other of the ends ofsaid third and fourth portions respectively, each of said semi-circularwith a first and a second semi-circular portion spaced o 7 portionshaving. an inner semi-circular bearing surface facing and extendingconcentric to the respective yoke axis, each of said inner bearingsurfaces being tangent to two of the other three bearing surfaces at apoint lying I in a plane extending through the two yoke axes; and: a

lightweightarcnrte portion located in opposed relation 'to each of saidsemi-circular portions, said lightweight arcuate portions" each havingan inner face i of semicircular shape forming with each of saidsemicirculart bearing surfaces a continuous bearing surface surroundingan aperture adapted to receive the outer race of a bearing.

References Cited inthe file of this patent UNITED STATES PATENTS 896,195Bogart; Aug. 18, 1908 1,381,600 Thiemer 1.. June 14, 1921 r 2,336,579Venditty etal; De; ;14;1 943 1,396,658 Goddard Dec. "16; 1952 Dec. 231958

1. IN A UNIVERSAL GIMBAL: AN ENDLESS BAR MEMBER FORMED WITH A FIRST ANDA SECOND ARCUATE PORTION SPACED ALONG A FIRST YOKE AXIS, AND THIRD ANDFOURTH ARCUATE PORTIONS SPACED ALONG A SECOND YOKE AXIS WHICH EXTENDS ATA RIGHT ANGLE TO SAID FIRST YOKE AXIS, THE ENDS OF SAID FIRST PORTIONBEING INTEGRALLY AND DIRECTLY JOINED TO ONE OF THE ENDS OF SAID THIRDAND FOURTH PORTIONS RESPECTIVELY, THE ENDS OF SAID SECOND PORTION BEINGINTEGRALLY AND DIRECTLY JOINED TO THE OTHER OF THE ENDS OF SAID THIRDAND FOURTH PORTIONS RESPECTIVELY; FOUR RADIAL BEARINGS EACH HAVING ANINNER AND AN OUTER RACE, EACH OF SAID BEARINGS BEING MOUNTED WITH ITSAXIS OF ROTATION PARALLEL TO ONE OF SAID YOKE AXES AND ITS OUTER RACEENGAGING A SEPARATE ONE OF SAID ARCUATE PORTIONS RESPECTIVELY, EACH OFSAID OUTER RACES BEING TANGENT TO TWO OF THE OTHER THREE OUTER RACES ATPOINTS LYING IN A PLANE PASSING THROUGH SAID TWO YOKE AXES AND AT WHICHPOINTS SAID ARCUATE PORTIONS INTEGRALLY JOIN ONE ANOTHER.